1. A normal kiss burns 6.4 calories per minute. A passionate kiss can burn up to 20 calories per minute. That's even more than swimming, which burns 12 calories in one minute, just like jumping rope.

Kissing seems like it would be one of those instinctive things humans do — like yawning, stretching, or scratching. After all, what is the big deal about two pairs of lips locking together? However, ...